We applied Modification of Diet in Renal Disease (MDRD) formula to calculate eGFR for DKD classification; nevertheless, other methods include (CKD-EPI)creatinine [22], CKD-EPIcystatin C [23] and CKD-EPIcreatinine–cystatin C [23] equations were calculated as well. Here, CST3 is linked to diabetic kidney disease.